Draglinescraper



Jan 21 1941- A. T. SPENCER, JR 2,229,351

DRAGLINE SCRAPER Filed June 19, 1959 2 Sheets-Sheet 1 l I l l l INVENTOR ATTORN EY Jan. 21, 1941. A, T SPENCER, JR f `2,229,351

DR AGL INE S CRAPER Filed June 19, 1939 2 sheets-sheet'z IT, Q

INVENTOR /4//0/7 pencer//v Patented Jan. '21, 1941 UNIE stares PATENT OFFICE DRAGLINE SCRAPER Allan'T.' Spencer, Jr., Gerber, Calif;

Application .lune 19, 1939, SeriallN. 279,872

2 Claims.

My invention relates to means for moving material, particularly earthy material, and is.

concerned especially with an earth scraper and carrier of the dragline type.

Devices of this general character are in common use for excavating and transporting earth, and it is a general object ofl my invention to limprove them.

It is a further object of. my invention to in- 105 crease the carrying capacity of a `dragline scraper, Aespecially by preventing inadvertent discharge of excavated earth therefrom.

Another object of my invention is to provide a positive opening and closing movement of` the =-earthretaining members of a dragline scraper.

An additional .object of my invention is to provide a dragline scraperv which, while having positive eartheretaining capacity, can bemoved into a position for complete discharge.

constructed in accordance with my invention, in

transporting position;

1, Fig. 3 is a side elevation similar to Fig.y 1,y but showing the dragline scraper in excavating position; and

Fig. 4 is a view in side elevation showing the dragline excavator in discharging position. l In its preferred form,fthe dragline scraper' of my invention includes .a mainvbowl to which is pivoted a front apron movable by means oi acrank arm, there being secured to -thefmain bowl a hoist line and from it an apron line attached to the front apron, and therevbein-g'secured to the crank arm a dragline and, branching from it, a control line which passes around a sheave secured to the hoist line and then extends to the crank arm. l

While the dragline scraper of my invention is susceptible of various modifications, depending upon various conditions of use or preferences of the designer, it is illustrated herein in an effective embodiment for general use.

The excavator is adapted to be utilized to ex- A further object of my invention is to providel Fig. 2 is a plan of thestructure shown in Fig.

dislodging and loosening the earth to be exca- 4.

vated, the leading edge of the bottom 8y provided with' a plurality ofV downwardly inclined excavating teeth I3-terminating in cuttingV edges M, so that the/earthy material vwill be cutgloose from its surroundings and willy slide'up'fthe inrcline .of the teeth I3 into the mainl bowl l. To assist the main bowl in excavating, and; alsovto retain earth which has been excavated, I-pro vide a front aprongenerally designa-ted I6'. Thisy is preferably fabricated of metal and includes a4 bottom I? merging with a front wall I8 andav .pair of side walls I9 and 2|. Extending-rearwardly from the bottom Il', and designedfto as sist in excavating, is a plurality of cuttingteeth 22 'oiiset with respect to the forwardly projecting members I3'sorthat `in closed position themem-A bers I 3 land 22 interengaga The-front apron I6 is preferablymountedon' v the main bowl for pivotal movement, and for that reason I provide either two short stub axles; if'

it is .important that theV main bowl b eunobstructed, or, if greater rigidity is desired, asingle" axle 23 extendingV across the main bowl sube stantially above the cutting vedge-I4. The stub` axles or, inthe prese-ntl case, the'single'axle'is rotatably mounted in upwardly extending ears '2,4' ontheside plates III and'IZ, reinforced byfad'di-v tional plates if desired. Preferably, theiaxle 23 is fastened to ears 26 upstanding from` thej'side' walls'fI-Q and-2lY oi the front apron, so that theapron tur-nsvwth rotation of the axle.

To provide'pivotal movement, Ywhen' desired," between the front apron' and-the mainjbowl, I likewise secure to-each of the stub axles orto the axlerESg outside-of 'the' side walls ofth'e' mainH bowl, a pair'of crank arms-21 and -29"; Theseare" i protected during excavation by arcuate guards" 29 secured to the side walls II and I2 andl` extending loutwardly .therefrom slightly beyondthe crank -arlns in' all positions thereof.` a

To move the dragline scraper and tocontrolits movement, I provide a pair of lines, namely, a hoist line and a drag line, which operate generally in conjunction but which are under the separate control of an operator for producing the various movements requisite and desired. The hoist line 3| includes a plurality of component parts, especially a cable 32 which is secured to a ring 33 joining a pair of chains 3i and 36 connected to eyes 31 adjacent the extremities of a horizontal spreader bar 38 of substantially the same width as the main bowl 1. Depending from the eyes 31 are hoist chains 4I and 42, depending substantially parallel to the sides II and I2 of the main bowl and terminating in pivotal connections 43 to reinforcing ears 44 secured to the side walls at points considerably to the rear of the center of gravity of the main bowl 1.

For assisting in controlling the front apron I6 I preferably extend an apron line I, such as a cable, from a fastening at one end to the ring 33 to a connection at the other end to a link 52 which itself is connected by a pivot 53 to ears 574V on the forward wall I8 of the front apron.

` The dragline 56 includes a plurality of Vcomponents, such as a cable 51 which is fastened to a link 58 on which an equalizer bar 59 is mounted by a pivot 6I. From the opposite extremities of the equalizer 59 drag chains 62 and 63 extend rearwardly around the sides I9 and 2I of the front-apron and terminate at their rearward ends in pivotal connections 64 to links 66 each of which is mounted on a pivot pin 61 at the lowermost extremity of the adjacent one of the crank arms ,i 2a and 29.

Also connected to the link 58 by a connector 53 is a pair of control lines 69 and 1I preferably constituted of cables, each of which extends over its associated one of a pair of sheaves 12 and 13, flexibly articulated to eyes 14 and 16 adjacent the outerextremi'tes of the bar 38. After passing around its sheave 12 or 13, each control line passes around one of a pair of idler pulleys 11 each mounted on a strap 18 having an offset central portion and freely pivoted on the axle 23. From its passage around the pulley 11, the control line passes around a second pulley 19 which is one of a pair journaled on ears 8| upstanding from the side walls II and I2 of the main bowl and located just above the pivot 61 when the front apron is in closed position. The con-trol line, after passing around the pulley 19, is connected at its extremity to the link 66 on the opposite side of the pivot pin 61 from the connec- 'tion 64.

When the dragline scraper is to be propelled forwardly to excavate, the hoist line 32 is left somewh-at slack and the dragline 51 is tautened. This is effective to tension the control cables 69 and 1I and also to tension the drag chains 62 and 63 so that the crank arms 28 are swung forwardly, suiiicient slack to provide for the forward movement of the pulleys 12 and 13 being allowed in the hoist line. The forward movement of the cranks 28 and 29 rotates the apron I6 into its open position, substantially as shown in Fig. 3, so that lthe tension of the drag cable 51 is exerted through the crank arms and through the control lines 69 and 1I a-t a point substantially at .the

center of gravity or slightly above or below it, the

and this change in forces moves the dragline 32 to maintain or even increase the tension upon the control lines 69 and 1I while permitting .the drag chains 62 and 63 to slacken if necessary, at least until .the crank arms 28 are moved from their apron-open position, as shown in Fig. 3, into their apron-closed position, -as shown in Fig. 1. This closing movement of the front apron is therefore effected positively so that the descending cutters 22 of `the apron bottom I1 are in themselves effective to cut through some of the earth 6 and to load additional material not only into the main bowl but also into the front apron, the

effect of the two parts of the dragline scraper 4.being in this respect similar to that of a clam shell bucket.

With an appropriate ratio between the tensions on the hoist line 32 and the dragline 51, exerted not so much through the drag chains 62 and 63 as through the control lines 69 and 1I, the dragline scraper is transported in substantially its position as shown in Fig. 1, from the excavating location to a discharging location. At the discharging location the drag line 5'1 is left somewhat slack, so that substantially the entire weight of the structure comes upon the hoist line 32. Since the points of connection 43 of the hoist line to the main bowl are considerably to the rear of the center of gravity thereof, the weight of the structure, as well as its contained load, is

' effective to move the parts substantially .to the discharging position shown in Fig. 4, the effect of the kcontrol lines 69 and 1'I during such movement being to urge a positive and full opening of the front apron I6. 63 may sometimes be somewhat slack, the line 5I is always effective to cause rthe front apron and the main bowl to move to a relatively open position, since, even without the line 51, the entire weight of the structure and its load is borne upon the lines 4I and 42 and upon the line 5I with an articulation therebetween so that the entire weight is effective to induce an opening or dumping movement.

After discharge, a lessening of the force on the hoist line 32 and an increase thereof on .the dragline 51, especially if the scraper is deposited upon the ground, restores the parts to excavating relationship, as shown in Fig. 3.

I claim:

1. A dragline scraper comprising a main bowl, a front apron pivoted thereon, va crank arm for pivoting said front apron overlying .the side of said main bowl, means for moving said crank arm to sweep over said bowl side, and an arcuate guide outstanding from said bowl side beyond the end of said crank arm.

2. A dragline scraper comprising a main bowl having sides, a front apron disposed between said sides and pivoted thereon, a pair of crank -arms secured to said front apron and externally overlying said sides, means for moving said crank arms for pivoting said front apron, and external guards on said sides adjacent the lends of said crank arms.

ALLAN T. SPENCER, JR.

But since the lines 62 and 

